1. Field of the Invention
This invention relates to a connector having connection terminals attached thereto for achieving an electrical connection in electrical wiring or the like, and more particularly to a connector of the type in which a groove for receiving an erroneous insertion prevention projection formed on a connection terminal to be inserted into a terminal insertion hole in a connector housing is formed at the terminal insertion hole.
2. Related Art
Various types of connectors have heretofore been used for connecting electrical wires together. In one of these connectors, an erroneous insertion prevention projection is formed on a connection terminal for preventing an erroneous insertion thereof when mounting the connection terminal within a connector housing, while a groove for receiving the erroneous insertion prevention projection is formed at a terminal insertion hole formed in the connector housing for receiving the connection terminal. A proper fitting condition is achieved when the erroneous insertion prevention projection is fitted in the groove.
FIG. 7 shows a basic construction of such a conventional connector.
The connector shown in this figure is used, for example, for achieving an electrical connection of a wire harness in an automobile or the like. A connection terminal 1, formed by blanking and bending a metal sheet has a tongue-like contact piece portion 2 at its distal end, and also has at its proximal end portion a clamping portion 3 for holding an insulative covering of a wire, as well as a clamping portion 4 for holding a conductor of the wire. This connection terminal also has an erroneous insertion prevention projection 5 formed by stamping at a lower side of an intermediate portion thereof, and further has a lance engagement portion 6 formed at an upper side of the intermediate portion.
A connector housing 9, having terminal insertion holes 8 for respectively receiving the connection terminals 1, is molded of an insulative synthetic resin. Referring to a basic construction of this housing, a groove 10 for receiving the erroneous insertion prevention projection 5, as well as a lance 11 which engages the lance engagement portion 6 to prevent withdrawal of the connection terminal 1 when this terminal is inserted into a predetermined position in the terminal insertion hole 8, are provided in the terminal insertion hole 8.
In the conventional connector, the groove 10 is disposed centrally of the width of each terminal insertion hole 8 as at 12 in FIG. 8.
In accordance with such arrangement of the groove 10, the erroneous insertion prevention projection 5, formed on the bottom of the connection terminal 1, is also disposed centrally of the width thereof as at 14 in FIGS. 9 and 10.
With this construction, the connection terminal 1 of this construction can be properly inserted into the terminal insertion hole 8 as shown in FIG. 11, so that the connection terminal 1 is disposed in a so-called normally-mounted condition in which the lance 11 completely retains the connection terminal 1 against withdrawal.
The contact piece portion 2 of the connection terminal 1 is adapted to be fitted into a female connection terminal mounted within a mating connector housing, and in order to facilitate the fitting, the front end portion of this contact piece portion is usually reduced in dimension in the directions of the thickness and width thereof. In the conventional construction, if the groove 10 has such a widthwise dimension W2 (see FIG. 8) as to receive the erroneous insertion prevention projection 5, this groove can perform its function, and the housing can be molded more easily if this widthwise dimension is relatively large. For this reason, this widthwise dimension has been larger than a widthwise dimension W1 (see FIG. 9) of the front end portion of the contact piece portion 2.
Therefore, if the connection terminal 1 is inserted into the terminal insertion hole 8 in such a manner that the front end of the contact piece portion 2 is generally directed toward the groove 10, the front end of the contact piece portion 2 falls in the groove 10, and engages the inner end of the groove 10. In some cases, this has prevented a smooth insertion of the connection terminal.
Recently, for labor saving purposes, the assembling of such a connector has now been carried out by automation, and the insertion of the connection terminal 1 into the terminal insertion hole 8 has been effected by an automation machine. In the automation machine, if there occurs an insertion error as shown in FIG. 12, the direction of insertion of the connection terminal 1 can not be easily corrected, as compared with a manual operation. Therefore, the operation must be finished in such an abnormal condition, and then the insertion operation must be carried out again to deal with this situation.